<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
  <head>
    <meta http-equiv="Content-Type" content="text/html;charset=UTF-8" />
    <style>
      body {
        margin: 0;
        padding: 0;
        overflow: hidden;
      }

      .city img {
        width: 100%;
      }
    </style>
    <title>放烟花模拟</title>
  </head>
  <body onselectstart="return false">
    <canvas id="cas" style="background-color: rgba(0, 5, 24, 1)"
      >浏览器不支持canvas</canvas
    >
    <img src="./img/moon.png" alt="" id="moon" style="visibility: hidden" />
    <div style="display: none">
      <!-- <div class="shape">新年快乐</div>
      <div class="shape">合家幸福</div>
      <div class="shape">HAPPY</div> -->
    </div>
    <audio src="./audio/boom.mp3" preload="auto"></audio>
    <audio src="./audio/boom.mp3" preload="auto"></audio>
    <audio src="./audio/boom.mp3" preload="auto"></audio>
    <audio src="./audio/boom.mp3" preload="auto"></audio>
    <audio src="./audio/boom.mp3" preload="auto"></audio>
    <audio src="./audio/boom.mp3" preload="auto"></audio>
    <audio src="./audio/shotfire.mp3" preload="auto"></audio>
    <audio src="./audio/shotfire.mp3" preload="auto"></audio>
    <audio src="./audio/shotfire.mp3" preload="auto"></audio>
    <script>
      var canvas = document.getElementById('cas');
      var ocas = document.createElement('canvas');
      var octx = ocas.getContext('2d');
      var ctx = canvas.getContext('2d');
      ocas.width = canvas.width = window.innerWidth;
      ocas.height = canvas.height = window.innerHeight;
      var bigbooms = [];

      window.onload = function () {
        initAnimate();
      };

      function initAnimate() {
        drawBg();

        lastTime = new Date();
        animate();
      }

      var lastTime;
      function animate() {
        ctx.save();
        ctx.globalCompositeOperation = 'destination-out';
        ctx.globalAlpha = 0.1;
        ctx.fillRect(0, 0, canvas.width, canvas.height);
        ctx.restore();

        var newTime = new Date();
        if (newTime - lastTime > 200 + (window.innerHeight - 767) / 2) {
          var random = Math.random() * 100 > 2 ? true : false;
          var x = getRandom(canvas.width / 5, (canvas.width * 4) / 5);
          var y = getRandom(50, 200);
          if (random) {
            var bigboom = new Boom(
              getRandom(canvas.width / 3, (canvas.width * 2) / 3),
              2,
              '#FFF',
              { x: x, y: y }
            );
            bigbooms.push(bigboom);
          } else {
            var bigboom = new Boom(
              getRandom(canvas.width / 3, (canvas.width * 2) / 3),
              2,
              '#FFF',
              {
                x: canvas.width / 2,
                y: 200,
              },
              document.querySelectorAll('.shape')[
                parseInt(
                  getRandom(0, document.querySelectorAll('.shape').length)
                )
              ]
            );
            bigbooms.push(bigboom);
          }
          lastTime = newTime;
        }

        stars.foreach(function () {
          this.paint();
        });

        drawMoon();

        bigbooms.foreach(function (index) {
          var that = this;
          if (!this.dead) {
            this._move();
            this._drawLight();
          } else {
            this.booms.foreach(function (index) {
              if (!this.dead) {
                this.moveTo(index);
              } else if (index === that.booms.length - 1) {
                bigbooms.splice(bigbooms.indexOf(that), 1);
              }
            });
          }
        });

        raf(animate);
      }

      function drawMoon() {
        var moon = document.getElementById('moon');
        var centerX = canvas.width - 200,
          centerY = 100,
          width = 80;
        if (moon.complete) {
          ctx.drawImage(moon, centerX, centerY, width, width);
        } else {
          moon.onload = function () {
            ctx.drawImage(moon, centerX, centerY, width, width);
          };
        }
        var index = 0;
        for (var i = 0; i < 10; i++) {
          ctx.save();
          ctx.beginPath();
          ctx.arc(
            centerX + width / 2,
            centerY + width / 2,
            width / 2 + index,
            0,
            2 * Math.PI
          );
          ctx.fillStyle = 'rgba(240,219,120,0.005)';
          index += 2;
          ctx.fill();
          ctx.restore();
        }
      }

      Array.prototype.foreach = function (callback) {
        for (var i = 0; i < this.length; i++) {
          if (this[i] !== null) callback.apply(this[i], [i]);
        }
      };

      var raf =
        window.requestAnimationFrame ||
        window.webkitRequestAnimationFrame ||
        window.mozRequestAnimationFrame ||
        window.oRequestAnimationFrame ||
        window.msRequestAnimationFrame ||
        function (callback) {
          window.setTimeout(callback, 1000 / 60);
        };

      canvas.onclick = function () {
        var x = event.clientX;
        var y = event.clientY;
        var bigboom = new Boom(
          getRandom(canvas.width / 3, (canvas.width * 2) / 3),
          2,
          '#FFF',
          { x: x, y: y }
        );
        bigbooms.push(bigboom);
      };

      var Boom = function (x, r, c, boomArea, shape) {
        this.booms = [];
        this.x = x;
        this.y = canvas.height + r;
        this.r = r;
        this.c = c;
        this.shape = shape || false;
        this.boomArea = boomArea;
        this.theta = 0;
        this.dead = false;
        this.ba = parseInt(getRandom(80, 200));

        var audio = document.getElementsByTagName('audio');
        for (var i = 0; i < audio.length; i++) {
          if (
            audio[i].src.indexOf('shotfire') >= 0 &&
            (audio[i].paused || audio[i].ended)
          ) {
            audio[i].play();
            break;
          }
        }
      };
      Boom.prototype = {
        _paint: function () {
          ctx.save();
          ctx.beginPath();
          ctx.arc(this.x, this.y, this.r, 0, 2 * Math.PI);
          ctx.fillStyle = this.c;
          ctx.fill();
          ctx.restore();
        },
        _move: function () {
          var dx = this.boomArea.x - this.x,
            dy = this.boomArea.y - this.y;
          this.x = this.x + dx * 0.01;
          this.y = this.y + dy * 0.01;

          if (Math.abs(dx) <= this.ba && Math.abs(dy) <= this.ba) {
            if (this.shape) {
              this._shapBoom();
            } else this._boom();
            this.dead = true;
          } else {
            this._paint();
          }
        },
        _drawLight: function () {
          ctx.save();
          ctx.fillStyle = 'rgba(255,228,150,0.3)';
          ctx.beginPath();
          ctx.arc(
            this.x,
            this.y,
            this.r + 3 * Math.random() + 1,
            0,
            2 * Math.PI
          );
          ctx.fill();
          ctx.restore();
        },
        _boom: function () {
          var fragNum = getRandom(100, 300);
          var style = getRandom(0, 10) >= 5 ? 1 : 2;
          var color;
          if (style === 1) {
            color = {
              a: parseInt(getRandom(128, 255)),
              b: parseInt(getRandom(128, 255)),
              c: parseInt(getRandom(128, 255)),
            };
          }

          var fanwei = fragNum;
          var audio = document.getElementsByTagName('audio');
          for (var i = 0; i < audio.length; i++) {
            if (
              audio[i].src.indexOf('boom') >= 0 &&
              (audio[i].paused || audio[i].ended)
            ) {
              audio[i].play();
              break;
            }
          }
          for (var i = 0; i < fragNum; i++) {
            if (style === 2) {
              color = {
                a: parseInt(getRandom(128, 255)),
                b: parseInt(getRandom(128, 255)),
                c: parseInt(getRandom(128, 255)),
              };
            }
            var a = getRandom(-Math.PI, Math.PI);
            var x = getRandom(0, fanwei) * Math.cos(a) + this.x;
            var y = getRandom(0, fanwei) * Math.sin(a) + this.y;
            var radius = getRandom(0, 2);
            var frag = new Frag(this.x, this.y, radius, color, x, y);
            this.booms.push(frag);
          }
        },
        _shapBoom: function () {
          var that = this;
          putValue(ocas, octx, this.shape, 5, function (dots) {
            var dx = canvas.width / 2 - that.x;
            var dy = canvas.height / 2 - that.y;
            for (var i = 0; i < dots.length; i++) {
              color = { a: dots[i].a, b: dots[i].b, c: dots[i].c };
              var x = dots[i].x;
              var y = dots[i].y;
              var radius = 1;
              var frag = new Frag(
                that.x,
                that.y,
                radius,
                color,
                x - dx,
                y - dy
              );
              that.booms.push(frag);
            }
          });
        },
      };

      function putValue(canvas, context, ele, dr, callback) {
        context.clearRect(0, 0, canvas.width, canvas.height);
        var img = new Image();
        if (ele.innerHTML.indexOf('img') >= 0) {
          img.src = ele.getElementsByTagName('img')[0].src;
          imgload(img, function () {
            context.drawImage(
              img,
              canvas.width / 2 - img.width / 2,
              canvas.height / 2 - img.width / 2
            );
            dots = getimgData(canvas, context, dr);
            callback(dots);
          });
        } else {
          var text = ele.innerHTML;
          context.save();
          var fontSize = 200;
          context.font = fontSize + 'px 宋体 bold';
          context.textAlign = 'center';
          context.textBaseline = 'middle';
          context.fillStyle =
            'rgba(' +
            parseInt(getRandom(128, 255)) +
            ',' +
            parseInt(getRandom(128, 255)) +
            ',' +
            parseInt(getRandom(128, 255)) +
            ' , 1)';
          context.fillText(text, canvas.width / 2, canvas.height / 2);
          context.restore();
          dots = getimgData(canvas, context, dr);
          callback(dots);
        }
      }

      function imgload(img, callback) {
        if (img.complete) {
          callback.call(img);
        } else {
          img.onload = function () {
            callback.call(this);
          };
        }
      }

      function getimgData(canvas, context, dr) {
        var imgData = context.getImageData(0, 0, canvas.width, canvas.height);
        context.clearRect(0, 0, canvas.width, canvas.height);
        var dots = [];
        for (var x = 0; x < imgData.width; x += dr) {
          for (var y = 0; y < imgData.height; y += dr) {
            var i = (y * imgData.width + x) * 4;
            if (imgData.data[i + 3] > 128) {
              var dot = {
                x: x,
                y: y,
                a: imgData.data[i],
                b: imgData.data[i + 1],
                c: imgData.data[i + 2],
              };
              dots.push(dot);
            }
          }
        }
        return dots;
      }

      function getRandom(a, b) {
        return Math.random() * (b - a) + a;
      }

      var maxRadius = 1,
        stars = [];
      function drawBg() {
        for (var i = 0; i < 100; i++) {
          var r = Math.random() * maxRadius;
          var x = Math.random() * canvas.width;
          var y = Math.random() * 2 * canvas.height - canvas.height;
          var star = new Star(x, y, r);
          stars.push(star);
          star.paint();
        }
      }

      var Star = function (x, y, r) {
        this.x = x;
        this.y = y;
        this.r = r;
      };
      Star.prototype = {
        paint: function () {
          ctx.save();
          ctx.beginPath();
          ctx.arc(this.x, this.y, this.r, 0, 2 * Math.PI);
          ctx.fillStyle = 'rgba(255,255,255,' + this.r + ')';
          ctx.fill();
          ctx.restore();
        },
      };

      var focallength = 250;
      var Frag = function (centerX, centerY, radius, color, tx, ty) {
        this.tx = tx;
        this.ty = ty;
        this.x = centerX;
        this.y = centerY;
        this.dead = false;
        this.centerX = centerX;
        this.centerY = centerY;
        this.radius = radius;
        this.color = color;
      };

      Frag.prototype = {
        paint: function () {
          // ctx.beginPath();
          // ctx.arc(this.x , this.y , this.radius , 0 , 2*Math.PI);
          ctx.fillStyle =
            'rgba(' +
            this.color.a +
            ',' +
            this.color.b +
            ',' +
            this.color.c +
            ',1)';
          ctx.fillRect(
            this.x - this.radius,
            this.y - this.radius,
            this.radius * 2,
            this.radius * 2
          );
        },
        moveTo: function (index) {
          this.ty = this.ty + 0.3;
          var dx = this.tx - this.x,
            dy = this.ty - this.y;
          this.x = Math.abs(dx) < 0.1 ? this.tx : this.x + dx * 0.1;
          this.y = Math.abs(dy) < 0.1 ? this.ty : this.y + dy * 0.1;
          if (dx === 0 && Math.abs(dy) <= 80) {
            this.dead = true;
          }
          this.paint();
        },
      };
    </script>
  </body>
</html>
